FIG. 1 shows a prior art feeding apparatus (02). Prior art feeding apparatus (02) comprises the following main components a first piston cylinder assembly (04), a second piston cylinder assembly (06), a third piston cylinder assembly (08), a first cylinder (10), a second cylinder (12), and a third cylinder (14), together with a plug disintegrator assembly (18), and a reactor feed screw assembly (22) to deliver the plugs to a reactor (104).
The first piston cylinder assembly (04) is comprised of: a first hydraulic cylinder (24), a first hydraulic cylinder front cylinder space (26), a first hydraulic cylinder rear cylinder space (28), a first hydraulic cylinder front connection port (30), a first hydraulic cylinder rear connection port (32), a first piston rod (34), a first hydraulic cylinder piston (36), a first hydraulic cylinder flange (38), and a first piston ram (40).
The first piston ram (40) is partly accommodated and arranged to travel in a reciprocating manner inside the first cylinder (10) which has associated therewith a feedstock inlet (42), a first cylinder first flange (44), and a first cylinder second flange (46). The first hydraulic cylinder flange (38) is connected to the first cylinder first flange (44).
The second piston cylinder assembly (06) is comprised of: second hydraulic cylinder (48), a second hydraulic cylinder front cylinder space (50), a second hydraulic cylinder rear cylinder space (52), a second hydraulic cylinder front connection port (54), a second hydraulic cylinder rear connection port (56), a second piston rod (58), a second hydraulic cylinder piston (60), a second hydraulic cylinder flange (62), and a second piston ram (64).
The second piston ram (64) is partly accommodated and arranged to travel in a reciprocating manner inside the second cylinder (12) which has associated with it a second cylinder first flange (66), a second cylinder second flange (68), a second cylinder third flange (70), and a cylindrical second pipe branch opening (72). The second hydraulic cylinder flange (62) is connected to the second cylinder first flange (66).
The first cylinder second flange (46) is connected to the second cylinder third flange (70) so as to allow a carbonaceous feedstock to be transferred through the first cylinder (10) by the advancing motion of the first piston ram (40) and partially compressed into the second cylinder (12) through the cylindrical second pipe branch opening (72).
The third piston cylinder assembly (08) is comprised of: third hydraulic cylinder (74), a third hydraulic cylinder front cylinder space (76), a third hydraulic cylinder rear cylinder space (78), a third hydraulic cylinder front connection port (80), a third hydraulic cylinder rear connection port (82), a third piston rod (84), a third hydraulic cylinder piston (86), a third hydraulic cylinder flange (88), and a third piston ram (90).
The third piston ram (90) is partly accommodated and arranged to travel in a reciprocating manner inside the third cylinder (14) which has associated with it a third cylinder first flange (92), a third cylinder second flange (94), a third cylinder third flange (96), and a cylindrical third pipe branch opening (98). The third hydraulic cylinder flange (88) is connected to the third cylinder first flange (92).
The second cylinder second flange (68) is connected to the third cylinder third flange (96) so as to allow a carbonaceous feedstock to be transferred through the second cylinder (12) by the advancing motion of the second piston ram (64) and partially compressed into the third cylinder (14) through the cylindrical third pipe branch opening (98).
After loose carbonaceous feedstock is transferred to the third cylinder (14) from the advancing motion of the second piston ram (64), the feedstock is then advanced through the third cylinder (14) by the advancing motion of the third piston ram (90) where it is compressed to develop a plug (100) of defined length and pressure to form the seal between the pressurized thermochemical reactor (104) and the feedstock inlet (42), which may be exposed to the atmosphere.
As seen in FIG. 1, the plug forms the primary seal between the pressurized thermochemical reactor (104) and the feedstock inlet (42). One of the three pistons is always in a closed position, which prevents a plug blow-out if the plug becomes unstable and provides additional safety against syngas leaks. L1 and L2 indicate the stroke starting position (L1) and maximum stroke length position (L2), respectively, of terminal plug-forming end of the third piston ram (90). In a preferred configuration, the compressible material is pressed to form a plug with a pressure of 10-1000 bars by the advancing movement of the third piston ram (90).
As plugs are successively formed they are transferred to a plug disintegrator assembly (18) which breaks up the formed plug for transference into the fluidized bed (102) of the pressurized thermochemical reactor (104) via a reactor feed screw assembly (22).
U.S. Pat. No. 7,964,004 shows an assembly which includes three single-acting pistons for use in a system of the sort seen in FIG. 1.